Cobalt resinate and method of



Patented Nov. 10, 1942' COBALT RESINATE AND METHOD OF PRODUCING Fred H. Lane, Hillsdale, N. Y., assignor to Hercules Powder Company, Wilmington, Del., a

corporation of Delaware No Drawing. Application September 4, 1941, Serial No. 409,540

7 Claims.

This invention relates to the production of fused cobalt resinates and more particularly to fused cobalt resinates of improved characteristics and to the method of production thereof.

The neutralization of wood or gum rosin with cobalt compounds to form the cobalt salt of the rosin acids has been described. The production of such cobalt resinates has been carried out either by fusing the rosin with a suitable cobalt compound or by a double decomposition procedure involving treatment of a water-soluble salt of a rosin with a soluble cobalt salt. By the double decomposition precipitation procedure neutral resinates have been prepared containing an amount of cobalt approximating the theoretical amount required to give the neutral salt such as cobalt diabietate. By the fusion method, however, it has been impossible to introduce more than a small amount of cobalt due to the fact that the fusion mixture sets to a solid mass or blocks, and consequently only acid resinates of low cobalt content have been possible by the fusion method.

It is an object of this invention to provide cobalt resinates of higher cobalt content than has been heretofore possible.

It is another object to provide fused cobalt resinates of high cobalt content which possess many improved characteristics.

It is a further object to provide a method of producing fused cobalt resinates of high metal content.

Other objects of the invention will appear hereinafter.

The above objects may be accomplished in accordance with this invention by fusing a polymerized rosin with a sufficient amount of a cobalt compound capable of reaction with the polymerized rosin, at a temperature in the range of about 200 C. to about 340 C. to give a cobalt resinate of the polymerized rosin having a cobalt content greater than the equivalent combining proportion of the polymerized rosin based on its acidity and as high as about 19% by weight. The theoretical cobalt content of a diresinate prepared from a rosin of theoretical acid number is 8.93%. This amount of cobalt thus represents the maximum obtainable in a resinate by the precipitation method and far exceeds the amount heretofore capable of introduction by a fusion procedure. By use of polymerized rosin as the rosin component and by use of the fusion process described it is possible, in accordance with this invention, to prepare cobalt resinates containing more than the theoretical combining proportion 55 may be of cobalt based on the acidity of the rosin and higher than that obtainable in the prior art fusion methods with ordinary rosin. Blocking difficulties are not encountered as in the case of ordinary rosins. Cobalt resinates containing a greater amount of cobalt and up to and exceeding twice the cobalt content of the cobalt resinates obtainable from ordinary rosin are thus made available as a result of the process of this invention.

In carrying out the process a polymerized rosin is reacted with a cobalt compound capable of reaction therewith to provide a salt. Such a compound may be a basic cobalt compound or it may be a cobalt salt of a volatil weak acid, or any other cobalt compound which under the fusion conditions liberates its cobalt. Suitable cobalt compounds are, for example cobalt acetate, cobalt lactate, cobalt butyrate, cobalt formate, cobalt oxide, mixtures of cobalt oxide with a fatty acid cobalt salt as the acetate, mixtures of cobalt oxide with a fatty acid as acetic acid, etc. In using cobalt oxide it is usually desirable to employ it in admixture with a fatty acid salt or a fatty acid since the reactivity of the oxide alone in some cases is not sufficient to provide homogeneous resinates. A small amount of calcium acetate or other fatty acid salt of calcium or a fatty acid salt of zinc, lead, manganese, etc., may be employed, if desired, with cobalt oxide to facilitate the reaction of the latter. When such auxiliary agents are used, they combine partially with the polymerized rosin also.

The reaction is performed by heating the polymerized rosin to a temperature in the range of about 200 C. to about 340 C. and adding the cobalt compound either gradually or at one time, preferably while agitating the mixture. Foaming occurs during the reaction and agitation serves to hold such foaming to a minimum. The foaming is more severe at the lower temperatures and the reaction is also slower. At temperatures above about 320 C. the reaction is vigorous and the yield becomes diminished due to volatilization of light ends from the polymerized rosin. Temperatures in the range of about 260 to about 320 C. are therefore preferred for the reaction.

The time of reaction to form the novel resinates is dependent on the temperatures employed, the particular cobalt compound used, the degree of agitation, the amount of metal being introduced, as well as other factors. Thus the reaction time may be varied from about 10 minutes to several hours. Presence of an inert atmosphere such as provided by carbon dioxide, nitrogen, flue gas, etc., prevents oxidation of the polymerized rosin and the resinate at the elevated temperatures employed and is therefore desirable, though not essential.

The polymerized rosins which may be employed in the process of the invention may be those derived from any of the various grades of Wood or gum rosin or the rosin acids contained therein as abietic acid, pimaric acid, sapinic acid, etc. They may be produced from such rosins or rosin acids by polymerization according to any of the known methods, such as for example, by treatment with various catalysts as sulfuric acid, organic substituted sulfuric acids, boron trifluoride, metallic halides, zinc chloride, aluminum chloride, hydrofluoric acid, or by treatment of the rosins with a high voltage, high frequency discharge or by treatment with an acid sludge formed by treatment of rosin with sulfuric acid such as described in an application, Serial No. 328,864, filed April 10, 1940, by Clell E. Tyler. The polymerization of rosin by any of the procedures such as mentioned above is carried out usually by treatment of the rosin dissolved in some suitable organic solvent. If desired the polymerized rosin may be purified or refined before preparation of the fused cobalt resinate. The polymerized rosins which are useful in this invention will be those having a drop melting point from about C. to about 100 C. above the melting point of the original rosin used in the polymerization. Thus they will have a drop melting-point within the broad range of about 90 C. to about 175 C. and preferably about 95 C. to about 150 C. They will have an acid number usually above about 100 and preferably from about 135 to about 185.

The improved cobalt resinates described in accordance with this invention will have melting points considerably above the melting point of any cobalt resinate heretofore obtained from ordinary rosin. Their coalescing temperatures will also be considerably higher. They will contain a higher percentage of cobalt than prior cobalt resinates. They will be clear, homogeneous resinous compositions and will be substantially neutral. They will be less subject to spontaneous ignition than the cobalt resinates prepared from ordinary rosin. They will therefore be considerably more useful as driers in paint compositions due to their higher metal content. They will also be more compatible with film forming materials than the comparable cobalt resinates of ordinary rosin.

The following specific examples illustrate the various embodiments of the invention:

Example 1 A polymerized Wood rosin prepared by'treatment of K wood rosin with sulfuric acid and having an acid number of 145 and a melting point (drop) of 98 C. was used in the preparation of a cobalt resinate in the following manner. Six hundred fifty parts by weight of the polymerized rosin were melted and heated to a temperature of 205 C. Addition of 500 parts by weight of cobalt acetate was then started in small portions at a time with agitation, while permitting the reaction to become complete before each subsequent addition of cobalt acetate, as evidenced by the reduction in foaming. The temperature was raised gradually during the addition. A total time of 100 minutes was required for the addition and the temperature was raised to a maximum of 320 C. during the reaction. The resinate obtained after cooling was a clear,

homogeneous resinous composition having a cobalt content of 15.5% and a drop melting point of 225 C.

Example 2 Six hundred fifty parts by weight of the polymerized wood rosin used in Example 1 were melted and heated to a temperature of 250 C. Addition of 650 parts by weight of cobalt acetate was then carried out in small portions at a time with continuous agitation, while allowing the reaction to become completed before each subsequent addition of cobalt acetate and while raising the temperature gradually. An atmosphere of nitrogen was present during the reaction. The total time required for the addition of the cobalt acetate was minutes, and the temperature was raised to a maximum of 320 C. during the addition. After completion of the reaction the resinate was cooled. It had a cobalt content of 19% and a drop melting point of 220 C. It was a clear, homogeneous resinous composition.

Example 3 A polymerized rosin obtained by polymerization of K wood rosin with boron trifluoride and having an acid number of 112 and melting point of 107 C. was converted into a cobalt resinate by heating 81 parts by weight of the polymerized rosin to a temperature of 285 C. and adding 39 parts by weight of cobalt acetate in small portions at a time with agitation. The time required for the addition was minutes, during which the temperature reached a maximum of 295 C. The resinate obtained after cooling was a clear,

homogeneous resin having a cobalt content of It will be understood that the details and examples hereinbefore set forth are illustrative only and that the invention as herein broadly described and claimed is in no way limited thereby.

What I claim and desire to protect by Letters Patent is:

1. A cobalt resinate of a polymerized rosin, said' resinate having a cobalt content greater than the equivalent combining proportion of the polymerized rosin but not in excess of about 19% by Weight.

2. A cobalt resinate of a polymerized rosin, said resinate having a cobalt content greater than the equivalent combining proportion of the polymerized rosin but not in excess of about 19% by weight, said polymerized rosin having been prepared by polymerization of rosin with sulfuric acid as a catalyst.

3. The method of producing a cobalt resinate of a polymerized rosin, said resinate having a cobalt content greater than the equivalent combining proportion of the polymerized rosin but not in excess of about 19% by weight, which comprises fusing a polymerized rosin with a cobalt compound capable of reaction with the polymerized rosin, in an amount sufiicient to give a resinate of the above defined cobalt content and at a temperature within the range of about 200 C. to about 340 C.

4. The method of producing a cobalt resinate of a polymerized rosin, said resinate having a cobalt content greater than the equivalent combining proportion of the polymerized rosin but not in excess of about 19% by weight, which comprises fusing a polymerized rosin with a' cobalt compound capable of reaction with the polymerized rosin, in an amount sufficient to give a resinate of the above defined cobalt content and at a temperature within the range of about 260 C. to about 320 C.

5. The method of producing a cobalt resinate of a polymerized rosin, said resinate having a cobalt content greater than the equivalent combining proportion of the polymerized rosin but not in excess of about 19% by weight, which oomprises fusing a polymerized rosin with cobalt acetate in an amount suflicient to give a resinate of the above defined cobalt content at a temperature within the range of about 200 C. to about 340 C.

6. The method of producing a cobalt resinate of a polymerized rosin, said resinate having a cobalt content greater than the equivalent combining proportion of the polymerized rosin but not in excess of about 19% by weight, which comprises fusing a polymerized rosin with cobalt oxide in an amount sufllcient to give a resinate of the above defined cobalt content and in the presence of a small amount or calcium acetate as catalyst at a temperature within the range of about 200 C. to about 340 C.

7. The method of producing a cobalt resinate of a polymerized rosin, said resinate having a cobalt content greater than the equivalent combining proportion of the polymerized rosin but not in excess of about 19% by weight, which comprises fusing a polymerized rosin with a mixture of cobalt oxide and cobalt acetate in an amount sufiicient to give a resinate of the above defined cobalt content at a temperature within the range of about 200 C. to about 340 C.

FRED H. LANE. 

